To understand the processes underlying the acquisition of skill and the control of movement is the goal of recent interdisciplinary research. Proprioceptive feedback relaying limb position and movement information to the central nervous system is generally thought to be an important element in the ongoing regulation of movement. However a major limitation in stuying the role of proprioceptive input in human motor behavior is that it is only remotely accessible to experimental manipulation. The patient who has undergone surgical joint replacement provides a preparation by which we can delineate the role of joint capsule receptor mechanisms and the type of information which they mediate. A series of experiments using a simple movement reproduction paradigm is proposed to assess the static and dynamic components of proprioception in normal subjects and joint replacement patients. Such experiments will be performed prior to and at systematic intervals following the surgical procedure in order to examine the pattern of recovery of sensorimotor function. While serving a theoretical goal, this research may also provide clinical personnel with quantitative diagnostic tools for evaluating a relatively neglected aspect of joint replacement.